Carburant Product Characteristics And Quality Requirements
Many types of Carburant, can be used as cast iron Carburant is also a lot of material, but the quality of great disparity, the price difference is also great, to ensure the quality of casting under the premise of the product should be based on the characteristics and quality requirements, Choose to increase Carburant.
Many types of Carburants, according to the use of most factories, only briefly introduced two commonly used Carburant:
Carbon is present in the form of simple carbon, the melting temperature is 3727 ℃, can not melt at the temperature of molten iron. Therefore, the carbon in the carbon is mainly dissolved in molten iron by dissolving and diffusing in two ways. When the wc = 1.0% of the molten iron, the graphite in the graphite can be dissolved directly in the molten iron. Rather than the direct phenomenon of graphite carbon does not exist, but with the passage of time, carbon in the molten iron gradually spread and dissolved. Therefore, for the furnace smelting synthetic cast iron by carbon, the use of graphite by carbon increased carbon speed was significantly higher than non-graphite Carburant.
There are many kinds of raw materials, there are many kinds of small carbon species, High-quality Carburant generally refers to the graphite by the Carburant, in high temperature conditions, the arrangement of carbon atoms in the micro-morphology of graphite, so called graphitization. Graphitization can reduce the amount of impurities in the Carburant, increase the carbon content of the Carburant, reduce the sulfur content.
The use of carbonizers in the casting can significantly increase the amount of scrap, reduce the amount of pig iron or no pig iron. Electric furnace smelting of the feeding method, the Carburant should be with the scrap and other materials into the inside together, the addition of small doses can be added to the surface of the molten iron. But to avoid large quantities of molten iron to feed, to prevent excessive oxidation and the effect of carbon is not obvious and the cast carbon content is not enough. The amount of Carburant added, according to the ratio of other raw materials and carbon content to be set. Different types of cast iron, according to the need to choose different types of Carburant. The characteristics of the Carburant itself choose pure carbon-containing graphitizing substances, reduce excess impurities in pig iron, the choice of Carburant can reduce the cost of casting production.
The composition of the Carburant should be distinguished by the composition of the nitrogen content. To add more than 50 --- 60% of the induction furnace scrap, smelting synthetic cast iron, the greater the amount of scrap, iron ore nitrogen content is also greater. As the synthesis of cast iron iron in the titanium, lead, antimony and other harmful elements is low, it should use low nitrogen Carburant. If the carbon content of the carbon is higher, it is easy to make the casting hole. In general, low-end Carburant nitrogen is relatively high.
As the content of titanium in molten iron is very low, it is impossible to consume a large amount of nitrogen with Ti, so that the casting is easy because of the nitrogen content is too high and the emergence of nitrogen holes, cracks, nitrogen holes or related defects. This phenomenon has been in my previous work occurred in the unit, many experts in their published articles also talked about the quality of carbonants to bring their bad loss, with particular emphasis on synthetic cast iron smelting, the key in the use of good quality Of the calcined petroleum coke with low nitrogen content. Many casting friends that the Carburant sulfur content is higher, will not affect the quality of ordinary gray iron (pregnant cast iron), but the Carburant with high sulfur, with the nitrogen will be high, bring quality problems.